mediagoblin/app.py

   1 # GNU MediaGoblin -- federated, autonomous media hosting
   2 # Copyright (C) 2011 MediaGoblin contributors.  See AUTHORS.
   3 #
   4 # This program is free software: you can redistribute it and/or modify
   5 # it under the terms of the GNU Affero General Public License as published by
   6 # the Free Software Foundation, either version 3 of the License, or
   7 # (at your option) any later version.
   8 #
   9 # This program is distributed in the hope that it will be useful,
  10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 # GNU Affero General Public License for more details.
  13 #
  14 # You should have received a copy of the GNU Affero General Public License
  15 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 import os
  18 import urllib
  19
  20 import routes
  21 from webob import Request, exc
  22
  23 from mediagoblin import routing, middleware
  24 from mediagoblin.tools import common, translate, template
  25 from mediagoblin.tools.response import render_404
  26 from mediagoblin.tools import request as mg_request
  27 from mediagoblin.mg_globals import setup_globals
  28 from mediagoblin.init.celery import setup_celery_from_config
  29 from mediagoblin.init import (get_jinja_loader, get_staticdirector,
  30     setup_global_and_app_config, setup_workbench, setup_database,
  31     setup_storage, setup_beaker_cache)
  32
  33
  34 class MediaGoblinApp(object):
  35     """
  36     WSGI application of MediaGoblin
  37
  38     ... this is the heart of the program!
  39     """
  40     def __init__(self, config_path, setup_celery=True):
  41         """
  42         Initialize the application based on a configuration file.
  43
  44         Arguments:
  45          - config_path: path to the configuration file we're opening.
  46          - setup_celery: whether or not to setup celery during init.
  47            (Note: setting 'celery_setup_elsewhere' also disables
  48            setting up celery.)
  49         """
  50         ##############
  51         # Setup config
  52         ##############
  53
  54         # Open and setup the config
  55         global_config, app_config = setup_global_and_app_config(config_path)
  56
  57         ##########################################
  58         # Setup other connections / useful objects
  59         ##########################################
  60
  61         # Set up the database
  62         self.connection, self.db = setup_database()
  63
  64         # Get the template environment
  65         self.template_loader = get_jinja_loader(
  66             app_config.get('user_template_path'))
  67
  68         # Set up storage systems
  69         self.public_store, self.queue_store = setup_storage()
  70
  71         # set up routing
  72         self.routing = routing.get_mapper()
  73
  74         # set up staticdirector tool
  75         self.staticdirector = get_staticdirector(app_config)
  76
  77         # set up caching
  78         self.cache = setup_beaker_cache()
  79
  80         # Setup celery, if appropriate
  81         if setup_celery and not app_config.get('celery_setup_elsewhere'):
  82             if os.environ.get('CELERY_ALWAYS_EAGER'):
  83                 setup_celery_from_config(
  84                     app_config, global_config,
  85                     force_celery_always_eager=True)
  86             else:
  87                 setup_celery_from_config(app_config, global_config)
  88
  89         #######################################################
  90         # Insert appropriate things into mediagoblin.mg_globals
  91         #
  92         # certain properties need to be accessed globally eg from
  93         # validators, etc, which might not access to the request
  94         # object.
  95         #######################################################
  96
  97         setup_globals(app=self)
  98
  99         # Workbench *currently* only used by celery, so this only
 100         # matters in always eager mode :)
 101         setup_workbench()
 102
 103         # instantiate application middleware
 104         self.middleware = [common.import_component(m)(self)
 105                            for m in middleware.ENABLED_MIDDLEWARE]
 106
 107     def __call__(self, environ, start_response):
 108         request = Request(environ)
 109
 110         # pass the request through our middleware classes
 111         for m in self.middleware:
 112             response = m.process_request(request)
 113             if response is not None:
 114                 return response(environ, start_response)
 115
 116         ## Routing / controller loading stuff
 117         path_info = request.path_info
 118         route_match = self.routing.match(path_info)
 119
 120         # By using fcgi, mediagoblin can run under a base path
 121         # like /mediagoblin/. request.path_info contains the
 122         # path inside mediagoblin. If the something needs the
 123         # full path of the current page, that should include
 124         # the basepath.
 125         # Note: urlgen and routes are fine!
 126         request.full_path = environ["SCRIPT_NAME"] + request.path_info
 127         # python-routes uses SCRIPT_NAME. So let's use that too.
 128         # The other option would be:
 129         # request.full_path = environ["SCRIPT_URL"]
 130
 131         ## Attach utilities to the request object
 132         request.matchdict = route_match
 133         request.urlgen = routes.URLGenerator(self.routing, environ)
 134         # Do we really want to load this via middleware?  Maybe?
 135         request.session = request.environ['beaker.session']
 136         # Attach self as request.app
 137         # Also attach a few utilities from request.app for convenience?
 138         request.app = self
 139         request.locale = translate.get_locale_from_request(request)
 140
 141         request.template_env = template.get_jinja_env(
 142             self.template_loader, request.locale)
 143         request.db = self.db
 144         request.staticdirect = self.staticdirector
 145
 146         mg_request.setup_user_in_request(request)
 147
 148         # No matching page?
 149         if route_match is None:
 150             # Try to do see if we have a match with a trailing slash
 151             # added and if so, redirect
 152             if not path_info.endswith('/') \
 153                     and request.method == 'GET' \
 154                     and self.routing.match(path_info + '/'):
 155                 new_path_info = path_info + '/'
 156                 if request.GET:
 157                     new_path_info = '%s?%s' % (
 158                         new_path_info, urllib.urlencode(request.GET))
 159                 redirect = exc.HTTPFound(location=new_path_info)
 160                 return request.get_response(redirect)(environ, start_response)
 161
 162             # Okay, no matches.  404 time!
 163             request.matchdict = {}  # in case our template expects it
 164             return render_404(request)(environ, start_response)
 165
 166         controller = common.import_component(route_match['controller'])
 167         request.start_response = start_response
 168
 169         # get the response from the controller
 170         response = controller(request)
 171
 172         # pass the response through the middleware
 173         for m in self.middleware[::-1]:
 174             m.process_response(request, response)
 175
 176         return response(environ, start_response)
 177
 178
 179 def paste_app_factory(global_config, **app_config):
 180     configs = app_config['config'].split()
 181     mediagoblin_config = None
 182     for config in configs:
 183         if os.path.exists(config) and os.access(config, os.R_OK):
 184             mediagoblin_config = config
 185             break
 186
 187     if not mediagoblin_config:
 188         raise IOError("Usable mediagoblin config not found.")
 189
 190     mgoblin_app = MediaGoblinApp(mediagoblin_config)
 191
 192     return mgoblin_app